During the DDSN process, a form of DDSN/Oxide/DDSN/Oxide/DDSN thin film stacking layers is mainly used, and the DDSN serves as an etching blocking layer in a damascene structure of an intermetal dielectric layer and is typically used in a 130 nm, 110 nm copper manufacturing process.
For the Chemical Vapor Deposition (CVD) device of AMAT Producer, DDSN is in contact with a metal copper (Cu) below during the DDSN process, and a copper oxide (CuO) is prone to be formed on a surface of the metal copper (Cu) when placed in the air. The existence of such copper oxide (CuO) may damage the adhesion between the copper (Cu) and the DDSN thin film, influence the reliability and qualification rate in the subsequent integration processes, and even cause peeling of the thin film from a product such that the product is scrapped. Before depositing the first layer of DDSN, a NH3 pre-treatment is carried out under a plasma environment using ammonia gas. In this way, the CuO can be removed by using hydrogen ion (H+) to reduce the copper oxide (CuO) to the copper (Cu). However, at the same time, because the main ingredient of the surface of the process chamber is aluminum oxide (Al2O3), the remaining hydrogen ion (H+) during the NH3 pre-treatment may corrode the surface of the process chamber (especially a showerhead) that has the main ingredient of aluminum oxide (Al2O3), thereby causing particle gathering. In addition, the remaining fluorine ion (F−) during a cleaning process using NF3 may also corrode the surfaces of the process chamber and the showerhead, which also causes particle gathering. Such corrosion to the process chamber may shorten the life of the showerhead, resulting in increased frequency of maintenance for the process chamber.